package netty.socketio;

public class Main {

    static {
        System.out.println("this is test1! ");
    }
    {
        System.out.println("this is test2! ");
    }
    public Main() {
        System.out.println("this is test3! ");
    }

    public static void main(String[] args){
        //Main main = new Main();

        int r = 4^6;
        //0100
        //0110
        //=
        //0010
        //System.out.println(r);

        int[] arr = {1,3,5,7,1,3,5,9};
        findNumAppearOnce(arr);
    }


    public static void findNumAppearOnce(int[] arr) {
        int result = 0;
        for (int i = 0; i < arr.length; i++) {
            result ^= arr[i];
        }
        System.out.println(result);
    }




}
